Louis Farrakhan in Detroit yesterday Photograph: Carlos Osorio/APCould it be that Louis Farrakhan, the ageing Nation of Islam preacher, has undergone a Damascene conversion?

The fiery minister, banned from entering Britain for "anti-semitic and racially divisive views", has called for world unity between religions.

"If Jesus and Muhammad were on this stage, they would embrace each other with love," Mr Farrakhan told thousands of supporters in Detroit in a speech billed as his last public sermon. "How come we ... can't embrace each other?"

The turning point seems to have come while Mr Farrakhan was recovering for a 12-hour operation to treat what started as "a pain in the anal area" and turned out to be a recurrence of prostate cancer.

In a recorded message on the Nation of Islam website, Mr Farrakhan says "words are not adequate to express my deep sense of personal gratitude" to people of various religions who sent flowers and goodwill cards after his "horrific operation".

Each of you can go back to your mosques, churches, cathedrals, synagogues, temples, cloisters, or wherever it is that you worship God, and say to your congregations that our God, by whichever name you call him, answers prayer.

Mr Farrakhan, who notoriously once labelled Judaism a "gutter religion", says pastors put their churches on fasts and Buddhists chanted for him. "There were Hebrew Israelites all over America, Africa and Israel who prayed for me," he says.

Earl Ofari Hutchinson, however, argues that Mr Farrakhan has already left a damaging mark on American society. He says:

Farrakhan inadvertently or deliberately hardened the racial fault lines. While he was the only black leader that blended the charisma and militant rhetoric to ignite the passions of many blacks, the downside was that wrapping the mantle of leadership tightly around one man reinforced the terrible notion that blacks speak and think with one voice on racial problems.